1. Field of the Invention
The present invention relates to a switch device with an indicator, and more particularly to an improved switch device with an indicator capable of detailed indication of an operation amount of a switch.
2. Description of the Related Art
Switch devices are conventionally used for setting an amount of control for various devices. For example, rotary volume switches and sliding switches are widely used. FIG. 7 shows a mixer device 100 used for recording, which is one example of an operation panel in which a large number of such switch devices are arranged. In such a mixer device 100, because it is necessary to instantly visually recognize the operation amount (the amount or level to which a switch device has been operated, moved, or adjusted) of many switch devices, an indicator 102 capable of visually indicating noticeable change is often provided. In particular, for the mixer device 100 which is often used in a dimly-lighted room, a light emitting indicator 102 which allows quick judgment of the operation amount of the switch device is widely used because such an indicator is easier to recognize and costs less to manufacture than number display type switches, for example.
As an example, FIG. 8 illustrates a switch device including a rotary volume switch (hereinafter simply referred to as a xe2x80x9cswitchxe2x80x9d) 104 and a plurality of LEDs 102a arranged annularly around the switch to constitute an indicator 102. More specifically, FIG. 8 shows an example in which the position of lit LED 102a is sequentially moved in accordance with the operation amount of an operation knob (hereinafter simply referred to as a xe2x80x9cknobxe2x80x9d) 104a of the switch 104. Increase in the operation amount results in increase in the number of lit LEDs. In the specific example shown in FIG. 8, the operation amount of the knob 104a is expressed by the lighting-up of LEDs up to the LED 102 at at the apex position.
Similar switch devices provided with such indicators are also used in, for example, an operation panel in an airplane cockpit, operation panels for various devices installed in a vehicle, and for electronic appliances. In any of these cases, it is necessary that the operation amount of the switch device can be visually recognized quickly and easily.
While mixer devices 100 shown in FIG. 7 come in a wide range of sizes, in all such devices the operation panel includes a great number of switches, such a as volume switches, sliding switches, push switches, and the like. In addition, various monitors and displays may also be disposed densely on the same single operation panel. Because the size of the various switches can only be reduced within a range where the operability of the switch is not impaired, the indicator 102 provided around the switch 104 is subjected to space limitation, as shown in FIG. 8. Similarly, the number of LEDs 102a constituting the indicator 102 is also limited. Typically, these LEDs 102 are disposed at intervals corresponding to units such as xe2x80x9ceach volume amountxe2x80x9d, xe2x80x9cevery even-numbered volume amountxe2x80x9d, xe2x80x9cevery fifth volume amountxe2x80x9d, or the like regarding the operation amount of the knob 104a, so that the operator can recognize the operation amount to be, for example, xe2x80x9cvolume 5xe2x80x9d or xe2x80x9cvolume 6xe2x80x9d in accordance with the number of the LEDs 102 which emit light. Accordingly, when the space for the indicator is limited, the sensitivity of the display of the indicator 102 must be reduced, which leads to a problem that the indication resolution of the operation amount is lowered. In particular, even though a volume switch, for example, is a switch which enables continuous adjustment of the operation amount of the switch, the indicator thereof can express the operation amount only intermittently when the number of states of the operation amount exceeds the number of LEDs 102 constituting the indicator 102. In this state, it cannot be said that the indicator 102 fully performs its intended function. While it is theoretically possible to provide a greater number of LEDs 102a to express a finer operation amount, such as every half unit, in fact it is not easy to increase the number of LEDs 102a because of the limitation space and cost limitations. Further, when the number of LEDs 102a are simply increased, it is necessary to set up an agreement regarding the indication patterns, for example, that two LEDs lighting up corresponds to xe2x80x9can operation amount of 1xe2x80x9d, and the amount of xe2x80x9c0.5xe2x80x9d or the like cannot be expressed adequately. This leads to increased risk of incorrect reading of the displayed information because of its increased complexity.
The present invention was conceived in view of the aforementioned problems of the related art and aims to provide a low cost switch device with an indicator which allows increased resolution of indication of an operation amount of a switch without increasing the number of light emitting elements of the indicator.
In order to achieve the above object, in accordance with one aspect of the present invention, there is provided a switch device with an indicator, said indicator indicating an operation amount of a switch by causing a light emitting element corresponding to an operation state of the switch to emit light, said switch device comprising an operation knob for operating the switch, and a control section for controlling light emission of said indicator in accordance with the operation amount of said operation knob, wherein said indicator includes a first light emitting element which emits light when the operation state of the switch is in a first state and a second light emitting element which emits light when the operation state of the switch is in a second state, and, when the operation amount of the operation knob lies between the first and second states, said control section changes at least one of the amount and color of light emission from either one of said first light emitting element and said second light emitting element to indicate an intermediate operation state of the switch.
Further, in order to achieve the above object, in accordance with another aspect of the present invention, there is provided switch device with an indicator, said indicator indicating an operation amount of a switch by causing a light emitting element corresponding to an operation state of the switch to emit light, said switch device comprising an operation knob for operating the switch, and a control section for controlling light emission of said indicator in accordance with the operation amount of said operation knob, wherein said indicator includes a first light emitting element which emits light when the operation state of the switch is in a first state and a second light emitting element which emits light when the operation state of the switch is in a second state, and, when the operation amount of the operation knob lies between the first and second states, said control section causes both the first and second light emitting elements to emit light to indicate an intermediate operation state of the switch.
With the above structure, in an indicator which can typically express the states only in two stages, a first state and second state, it is possible to express states at least in three stages. Further, when the amount or color of light emission from a light emitting element is changed in a multistage manner, further multistage expression can be achieved, so that the indication resolution can be increased easily.
In accordance with another preferred aspect of the present invention, the control section changes the amount or color of light emission in a multistage manner to indicate the intermediate operation state of the switch.
Further, in accordance with another preferred aspect of the present invention, the first light emitting element and the second light emitting element are disposed adjacent to each other.
Still further, in accordance with another preferred aspect of the present invention, the indicator includes an attention point provided for indicating a predetermined operation amount of the operation knob.
Moreover, in accordance with another preferred aspect of the present invention, when the operation amount of the operation knob passes the attention point, the control section makes the light emission pattern of the indicator before the attention point different from the light emission pattern of the indicator after the attention point.
Further, in accordance with another preferred aspect of the present invention, the control section controls lighting of the indicator on the right or left side of the attention point which serves as a base point, in accordance with the operation amount of the operation knob in the right or left direction.
Still further, in accordance with another preferred aspect of the present invention, the control section controls lighting of the indicator on the right and left sides of the attention point simultaneously, using the attention point as a base point, in accordance with the operation amount of the operation knob.
Further, in accordance with another preferred aspect of the present invention, the control section causes a plurality of successive light emitting elements to selectively light up in accordance with the operation amount of the operation knob, so that the lighting position of the indicator moves such that the lighting pattern of the indicator LEDs appears to move around the switch in a wave or pulse which appears to grow by extending and shrinking, similar to the movement of an inchworm as viewed from above.
With these configurations, in an indicator which is composed of the limited number of light emitting elements, further stages can be indicated to thereby increase the indication patterns and the indication resolution.
It should be noted that while the present invention will be understood more clearly with reference to the following description of a preferred embodiment, the scope of the present invention is not limited to the embodiment.